Barriers for use on roadways are commonly used for security and law enforcement. An example of a situation where a barrier is desired is a high speed pursuit where law enforcement officers desire to immobilise a fleeing vehicle. An effective method that is used to accomplish this task is the use of upstanding spikes or blades on a roadway for piercing the fleeing vehicle's tires in order to deflate the tires and immobilise the vehicle. These devices are generally portable and not meant for long term use, requiring an individual to place and remove the device every time it is to be used.
Known devices which are permanently installed are found in low speed access lanes for parking lots and the like. These devices generally make use of some form of grill having numerous openings for inserting the spikes therethrough. These known devices do not adequately protect the spikes in an unarmed position and may allow tampering with the spikes by unauthorised persons. The devices are also easily tampered with by jamming anything into the openings of the grill. In some known devices a bent spike can easily jam within one of the openings, also resulting in damage to the device. Inadequate covering also results in weather penetration and icing in colder climates.